Executes one of a sequence of alternate statement blocks in
    a compound statement of a multistatement procedure. Unlike
    the simple CASE control statement, the searched CASE control
    statement supports arbitrary predicates for the WHEN clause that
    can contain variable and parameter references.

1  –  Environment

    You can use the searched CASE control statement in a compound
    statement of a multistatement procedure:

    o  In interactive SQL

    o  Embedded in host language programs to be precompiled

    o  As part of a procedure in an SQL module

    o  In dynamic SQL as a statement to be dynamically executed

2  –  Format

  case-searched-statement =

  CASE -----+--> WHEN -> predicate -> THEN -----+
            |  +--------------------------------+
            |  +-+-> compound-use-statement -+-++
            |    +------------ <-------------+ ||
            +----------------- <---------------+|
    +-------------------------------------------+
    +-+--------------------------------------+--> END CASE -->
      +-> ELSE -+-> compound-use-statement -++
                +------------- <------------+

3  –  Arguments

3.1  –  ELSE

    Specifies the set of SQL statements to be executed when the WHEN
    clause evaluates to FALSE or UNKNOWN.

3.2  –  THEN

    Specifies the set of SQL statements to be executed when the WHEN
    clause evaluates to TRUE.

3.3  –  WHEN

    Determines whether the compound use statements in the THEN clause
    are to be executed or the compound use statements in the ELSE
    clause are to be executed. If the predicate evaluates to TRUE,
    then the compound use statements in the THEN clause are executed.
    If the predicate evaluates to FALSE or UNKNOWN, then the compound
    use statements in the ELSE clause are executed.

4  –  Examples

    Example 1: Specifying Predicates with Variable References

    SQL> CREATE TABLE T (C INT);
    SQL> BEGIN
    cont> DECLARE :V INTEGER = 10;
    cont> DECLARE :X INTEGER = 0;
    cont> CASE
    cont>   WHEN :V = 1 THEN INSERT INTO T(C) VALUES (:X + 1);
    cont>   WHEN :V = 2 THEN INSERT INTO T(C) VALUES (:X + 2);
    cont>   WHEN :V > 3 THEN INSERT INTO T(C) VALUES (:X);
    cont>   ELSE INSERT INTO T(C) VALUES (-1);
    cont> END CASE;
    cont> END;